Electrical heating attachment for aerosol cans



' April s, 1969 l c. s. GARDNER 3,437,791

ELECTRICAL HEATING ATTACHMENT EoEAERosoL cANs vFiled Oct. 21, 1965 E 95INVENTOR United States Patent O U.S. Cl. 219-301 3 Claims ABSTRACT OFTHE DISCLOSURE A heating attachment detachable securement to the val-vestem of an aerosol can has a sealed chamber with a discharge passageextending therethrough. The passage is in comm-unication with the valvestem and receives products discharged from the can. A thermostaticallycontrolled electric heating coil is provided about the passage to heatthe discharged products. A gravity operated switch in the housingpermits energization of the heating coil only when the can is tilted.Short circuit protection is provided by fuses located in the plugportion of the attachment power cord. An adapter permits use of theattachment with cans having horizontally oriented discharge valves.

This invention relates to heating means and more particularly to anelectrical heating unit particularly adapted to be lutilized incombination with aerosol cans. The invention is an improvement of U.S.Patent 3,069,528, issued Dec. 18, 1962, to Charles S. Gardner.

The heating unit disclosed in the above identified patent performsadmirably to provide heated shaving cream foam at an optimal temperaturefor the most comfort in shaving. When used, and stored properly, thereis little danger that it will overheat. Inasmuch as there is thepossibility that it will not be, however, it would be particularlydesirable to have incorporated therein a control device to prevent itfrom overheating. Also, there is a possibility that the heating unit may-be dropped and damaged to the extent that a leak may develop throughcracks or breaks in the outer casing, or through separations in jointsof abutting portions of the composite casing, or through the apertureadmitting the electrical wires, or through the nozzle itself. Suchleakage could allow conductive liquid (water or other similar liquid) toproduce a short circuit which may be hazardous to the user. In thisrespect, it would also be desirable to incorporate in the heating unit asafety device to eliminate this hazard. The heating unit of the aboveidentified patent is adapted to fit only one type of aerosol nozzle. Atthe present time there are many nozzles, for example, side orientednozzles to which the heating unit of said patent cannot be adapted.Accordingly, it is an object of this invention to provide an improvedheating unit and particularly a heating unit which is adapted for usewith aerosol cans to heat the contents of the can as the contents isdischarged.

It is another object to provide fan improved heating unit of the typedescribed having a safety control device to preclude its overheating.

It is a further object to provide an improved heating unit of the typedescribed having a safety control device for eliminating electricalhazard to the user.

Still another object is to provide an improved heating unit which isadapted for use with various types of aerosol nozzles.

Other objects and advantages to be derived from the present inventionwill be obvious in the following description and enumeration of theaccompanying drawing in which:

FIG. l is a sectional view of a heating unit exemplary of the invention,including the male electrical plug, and including the valve stem portionof :a typical vertically oriented aerosol valve;

FIG. 2 is an elevational front view showing the heating unit of FIGURE 1mounted on atypical aerosol can having a vertically oriented aerosolnozzle;

FIG. 3 is an elevational front view showing the heating unit of FIGURE lmounted on fan aerosol can having a horizontally oriented aerosolnozzle;

FIG. 4 is a top plan view of an adapter for tting the heating unit ofFIGURE 1 to a horizontally oriented aerosol nozzle;

FIG. 5 is a sectional view taken substantially along lines 5 5 of FIGURE4; and

FIG. 6 is a sectional view taken substantially along lines 6-6 of FIGURE5.

Similar reference characters refer to similar parts of the originalinvention and throughout the several views of the drawing.

Referring now to the drawing, and particularly to FIG- URE 1 thereof,the numeral 20 represents a heating unit which can be affixed to thevalve stem 12 of an aerosol valve (not shown) for heating efliuent foam,such as shaving cream foam, as it is discharged from an aerosol can 10(FIG. 2). The valve stem is urged into its normally closed position by aspring (not shown) within the aerosol valve which fabuts liange 16. Inthe conventional usage of the aerosol can 10, the can 10 is'inverted andfinger pressure is applied on the valve stem 12, to operate the normallyclosed aerosol valve. The pressure within the can 10 will then force thecontents thereof outwardly through a cavity 77 in the valve stem 12.Upon the release of finger pressure, the spring will carry the valvestem 12 back to its normal position to thereby close the valve. Threads18 may be provided on the exterior surface of Valve stem 12 forthreadably receiving a cap thereon, however, in most cases the cap ispress-fitted onto the valve stem, or to the aerosol can.

The heating unit 20 further includes a frustro-conical shell 22 which ispreferably of an insulative generally rigid material such as plastic. Abase 24 having a tubular boss 26 integrally formed therewith is aixedwithin the ybase 24, extending with the boss 26 upwardly toward the apexof the frustro-conical shell 22. A counterbored passage is providedthrough the tubular boss 26 and includes a wide upper portion 28 and alower portion 29 which may have internal threads 30 formed therein forreceiving a valve stem having threads 18. A shoulder 32 separates thetwo portions 28 and 29 of the counterbore passage.

An insulative washer 34 is fixed in the upper portion 28 of the bosspassage and is seated on shoulder 32. The insulative washer 34 ispreferably inserted into the mold in which the base 24 is `cast and isintegrally cast therewith so that a longlasting effective moisture sealis provided. The base 24 is also preferably cast about a pair ofelectrical wires 48 and 50, as at S6, thereby sealing another aperturein the overall casing against moisture. With this construction, thepossibility of creating an electrical hazard due to leakage isminimized.

A tubular ceramic member 36 is received in the insulative Washer 34 sothat it is aligned with the valve stem 12. The frusto-conical shell 22is truncated near its apex and another insulative washer 40` is affixedwithin an aperture 42 formed therein. The washer 40 is forcibly seatedand retained within the annular shoulder 44 so that it cannot be easilyremoved and provides a goodseal. The ceramic -member 36 is forcedthrough and terminates in the washer 40. A good seal is therefore alsoprovided about the ceramic member 36, to prevent leakage. It is apparentthat a discharge path is provided from the can 10 through the valve stem12, through the ceramic member 36.

An electrical heating element 46 is placed about and preferably incontact with the ceramic member 36 in such a manner as to effect an evendistribution of heat about the periphery of the entire length of theceramic member 36. The heating element 46 is preferably fabricated ofNichrome or similar high heat intensity material so that efficient rapidheating is provided. The conductors 48 and 50 are connected in thefollowing manner to complete an effective operative circuit:

Conductor 48 is connected, as at 49, to a ring portion 51 of abimetallic thermostat 52, which ringed portion is rigidly sandwichedinbetween an insulative washer 35 and the flush surface resulting fromthe precast union of washer 34 and the top of the boss 26. At the upperportion (as shown) of the thermostat 52 there is aixed a contact 53which in its normal position physically touches another mating contact54 which is connected to the upper terminus 58 of the heating element46. The lower terminus 59 of the heating element 46 is connected, at 68,to a terminal 66 of a gravity operated switch 62, which may be a mercuryswitch. The other terminal 67 of the switch 62 is connected, as at `60,to the conductor 50 to complete the operative electrical circuits.

The switch 62 is aixed within the shell 22 rso that the switch 62 isnormally open. It may be easily glued and/or taped, -as with tape 64, tothe lboss 26 in proper position prior to inserting the base 24. It willbe apparent that upon inverting the aerosol can 10, the pool of mercury70 (in the event the switch 62 is a mercury switch) will move to aposition so as to electrically bridge the terminals 60 and 66 toenergize the heating element 46. The conductors 48 and 50 may betherefore permanently connected to an electrical energy source ifdesired, and the heating element will not be energized until the aerosolcan 10, or the heating unit 20, is inverted to close the terminals 60and 66.

An electrically insulative sleeve 75 is preferably positioned about theelectrical heating element 46 to prevent misalignment thereof and tofurther direct heat therefrom to the ceramic member 36. A centralpassage in the ceramic :member 36 includes perpendicular paths 74 and 76which have cross sections which may be cruciform in shape, star-shaped,liuted, corrugated or spiraled to provide optimal heat dispersementthroughout and within the ceramic member. The exterior surface of theceramic member 36 may be formed in the same manner, if desired.

In operation, the user places the heating unit 20 on the valve stem 12of the aerosol can 10, either by force fitting it or, if the valve stemis threaded, as illustrated, by threadably engaging the lower portion 30of the passage through the boss 26 with the threads of the valve stem.As noted above, the electrical conductors 48 and 50 may be leftconnected to a conventional electrical outlet or receptacle, and thenormally open gravity switch 62 will prevent current flow through theheating element 46. When ready to use, the aerosol can is simplyinverted and nger pressure is applied to the heating unit 20, to operatethe valve stem 12, in the well known manner. Upon inverting the aerosolcan 10, the gravity contact of the switch 62 will bridge the electricalterminals 60 and 66 thereby closing the electrical circuit so thatcurrent flows through the heating element 46. The contents dischargedthrough the valve stem 12 to the passage in the ceramic member 36- willbe heated as it passes through the passages 74 and 76 in the ceramicmember 36.

The thermostat device 52 included in the above described circuitryprecludes inadvertent or deliberate overheating of the heating element46. The bimetallic material on heating due to current flow through theheating element 46 will bow, in the well known manner, to open contacts53 and 54 to thereby prevent further current flow through the circuitincluding heating element 46. When I the bimetallic material cools,contacts 53 and S4 will again close. It may therefore be seen that ifthe heating unit 20, or an aerosol can with the unit affixed isaccidentally tipped over and left in an inverted position, 4the heatingelement 46 would heat up, but the thermostat 52 would prevent it fromoverheating to the extent of damaging the heating unit 20.

A further safety element has been combined with the heating unit 20 inthe form of a dual fused male electrical plug of a conventional variety.The plug 80 consists of low amperage fuses 81 and 82 electricallyconnected in series with conductors 48 and 50 respectively between maleprongs 83 and 84 respectively of the plug '80. A plug of this type isdesigned to permit only a low amperage current, and if a short circuitshould develop, the fuse material will immediately melt to preventelectrical shock to the user. The heating unit 20, of course, isthereafter inoperable until the plug 80 is replaced, but this is ofminor importance when compared to the protection it affords a user inthe event a short circuit should develop.

In FIGURE 3, the heating unit 20 is illustrated affixed to an aerosolcan 10 having a horizontally oriented valve stem 86. A valved button 85which, in some cases, may be rotatable, maybe provided to operate theaerosol valve (not shown) to discharge the contents of the can. Mosthorizontally oriented valve stems have a cross sectional shape that iseither rectangular or semicircular.

As is partially seen in FIGURE 3 and as shown in more detail in FIGURES4, 5 and 6, an adapter 90` ts over the end of a horizontally orientedvalve stem, such as valve stern 86, and is precluded by the pressurizedcontents from being forced from and olf of the valve stern by anintegrally formed ring 96 which slips over the shoulder portion of thevalve assembly.

The adapter is preferably of a resilient type material, such as plastic,and has a shank 91, a tapered portion 92, an annularly disposed barrelor stem portion 93 and an integral retaining ring 96. A central passage95 is formed through the stem 93 and intersects a main cavity 97 whichis preferably semicircular in shape, formed in the shank 91. The stemportion 93 may be threaded, in the manner described above, for use witha threaded valve stem. A number of annular serrations 98 are formed inthe wall of the cavity 97 and a rectangular shaped cavity 99 separatesthe main cavity 97 from the passage 95. With this construction, it isfound that a valve stem which is semicircular in cross section will abutthe outer most wall of rectangular cavity 99, and one which isrectangular in cross section will extend beyond the semicircular maincavity 97 and into the rectangular cavity 99. A good seal is thereforeprovided to prevent escape or leakage of the contents of the can as itis being discharged. The adhesive nature of the resilient material andthe annular serrations 98 which function as fingers to grip a valve stemcooperate to provide a good seal about horizontally oriented valvestems. The stem 93 is angularly disposed to prevent actuation of thegravity operated switch 62 while the aerosol can is setting in itsnormal upright position. When the aerosol can is tilted and the aerosolvalve operated, the contents are heated during discharge through theceramic member 36, in the manner described above.

It will thus be seen that the objects set forth above among those madeapparent from the preceding description, are eiciently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the -above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which, as amatter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new anddesired to be secured by Letters Patent is:

1. A heating attachment for use with aerosol cans having an aerosolvalve with a valve stem to heat the contents thereof as it is dischargedfrom lsaid cans comprisinlg: an adapter having a ring adapted to beafhxed to an aerosol can for securing said heating attachment to saidcan, a body portion having a valve stem cavity therein, said valve stemcavity having a plurality of serrations forming gripping teeth formed inits wall and a chamber adapted to receive the end of said valve stem toseal it therein, and a nozzle integrally formed with said body portionand angularly disposed substantially horizontally therewith; a heatingdevice including a base having an aperture which is adapted to receiveand to retain said nozzle therein; a tubular member dening a dischargepassage having one end sealed within said aperture; a hollow shellathxed to said base and to the opposite end of said tubular member so asto form a sealed chamber therein; electric heating means adapted to heatsaid tubular member enclosed within said chamber; a source of powerconnected to said electric heating means; gravity operated switch means;and a thermostat, said switch means and said thermostat being enclosedwithin said chamber and serially included in the connections betweensaid heating means and said source of power and operable to control theinitial energization of said heating means and to prevent it fromoverheating.

2. A heating attachment for use with aerosol cans having an aerosolvalve with a valve stem to heat the contents thereof as it is dischargedfrom `said cans comprisimg: an adapter having a ring adapted to beatixed to an aerosol can for securing said heating attachment to saidcan, a body portion having a valve stem cavity therein, said valve stemcavity having a plurality of serrations forming gripping teeth formed inits wall and a chamber adapted to receive the end of said valve stem toseal it therein, and a nozzle integrally formed with said body portionand angularly disposed substantially horizontally therewith; a heatingdevice including a molded base having an enlarged end, an upstandingmember integrally formed with said end and an aperture extending throughsaid end and said upstanding member which is adapted to receive andretain said nozzle therein; sealing means having an aperture thereinmolded into the upstanding member at its end during the molding of saidbase to provide a leakproof seal; a tubular member defining a dischargepassage having one end sealed within said aperture in said sealingmeans; a hollow shell aixed to said enlarged end of said base and to theopposite end of said tubular member so as to form a sealed chambertherein; electric heating means disposed about said tubular member; asource of power; a pair of conductors for connecting said heating meansto said source of power, said pair of conductors extending throw-gh saidbase and being molded therein during the molding of said base to providea leakproof seal; a gravity operated switch aixed to said upstandingmember in a fashion such that it is normally open and will close whentilted to a predetermined angular position; and a thermostat, saidswitch and said thermostat being enclosed within said chamber andserially included in the connections between said heating means and saidsource of power and operable to control the energization of said heatingmeans and to prevent it from overheating.

3. A heating attachment, as claimed in claim 2, further including plugmeans affixed to one end of said pair of conductors including shortcircuit protection means for disconnecting said heating means from saidsource of power in the event a short circuit develops.

References Cited UNITED STATES PATENTS 2,777,916 1/ 1957 Cooper 200-1153,069,528 12/1962 Gardner 219--280 3,098,925 7/1963 Fouts 219-2143,116,403 12/1963 Carter 219-301 3,144,174 8/ 1964 Abplanalp 239-135ANTHONY BARTIS, Primary Examiner.

U.S. CI. X.R.

